Food glycaemic index or meal glycaemic response?

We have studied the glycaemic response to 50 g of carbohydrate (CHO) within a standard meal in order to ascertain the usefulness of the glycaemic index of food high in CHO for planning the diabetic diet. Carbohydrate was given in the form of three kinds of food: rice, potatoes and lentils, each having a different glycaemic index. Four types of standard meals were prepared with different energy distributions. A1,2,3: 60 per cent CHO, 10 per cent protein, 30 per cent fat and 1.35 MJ (322 kcal); A4,5,6: 60 per cent CHO, 30 per cent protein, 10 per cent fat and 1.37 MJ (327 kcal); B1,2,3: 40 per cent CHO, 20 per cent protein, 40; per cent fat and 2.08 MJ (498 kcal); B4,5,6: 40 per cent CHO, 40 per cent protein, 20 per cent fat and 2.08 MJ (499 kcal). The increase in postprandial blood glucose levels at 30 min was lower when lentils were given than with rice or potatoes in all four types of energy distribution used (P less than 0.01). No differences were found at the other times studied. The slope from time 0 to maximal increase of glycaemia was lower with lentils in meals B1,2,3 (P less than 0.006) and B4,5,6 (P less than 0.007) but not in A1,2,3 or A4,5,6. Areas under the curve of the glycaemic responses elicited by the foods studied were similar with all four types of energy distribution used. These similar glycaemic responses were unexpected since the three foods used have different glycaemic indices.(ABSTRACT TRUNCATED AT 250 WORDS)